/*
 * VecAngle - vectors to angles
 *
 * Copyright 2008 James W. Hofmann
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

package lib3f;

class VecAngle
{

	public static function dotproduct(vec1 : Array<Float> ,
									  vec2 : Array<Float> )
	{
		var result = 0.0;
		for (n in 0...vec1.length)
			result+=vec1[n]*vec2[n];
		return result;
	}

	public static function normalize(x : Float, y : Float) :
		Array<Float>
	{		
		var dist = lib3f.Dist.float(0,x,0,y);
		return [x/dist, y/dist];
	}

	public static function vecangle(polarx : Float, polary : Float)
	{
		// returns the interval 0,2pi
		
		if (polarx>0 && polary>=0)
			return Math.atan(polary/polarx);
		else if (polarx>0) // && polary<0)
			return Math.atan(polary/polarx)+2*3.14159;
		else if (polarx<0)
			return Math.atan(polary/polarx)+3.14159;
		else if (polary>0) // && polarx==0)
			return 3.14159/2;
		else //(polarx==0 && polary<0)
			return 3*3.14159/2;
	}


}
